The fate of 14C-elastin in the peritoneal cavity of rats. I. Biochemical studies.

Degradation of elastin was studied in rats after intraperitoneal implantation of a suspension of 14C-elastin that had been prepared by labeling bovine elastin with 14C-formaldehyde. Most of the degradation of 14C-elastin, measured by releasing the radioactivity in urine and feces, occurred between 6 and 15 days after the implantation. During this period an increase of leukocytes and macrophages in the implanted site was observed. This followed a brief increase in neutrophils. Furthermore, an elevation of the elastolytic activity, measured by the 14C-elastin, was found in cell lysates of both macrophages and neutrophils, which were recovered by lavage of the peritoneal cavity. But the enzymatic activity was not found in the cell-free lavage. On the contrary, there was elastase inhibitor in the lavage, increased by the implantation. The mechanism of the elastin degradation in the peritoneal cavity was discussed.